Anglian Water uses cutting-edge flood risk data to boost climate resilience

Water treatment plant from above

Project facts

  • Client
    Anglian Water
  • Location
    Peterborough, UK
  • Challenge
    Reviewing and assessing the risk of flooding to Anglian Water’s 7,000 above-ground assets for its PR24 business plan.
  • Solution
    Anglian Water used Twinn FloodScore Climate data to screen assets and identify those at highest risk. A Royal HaskoningDHV team then conducted site visits at 25 high-risk sites.
  • Impact
    Anglian Water has enhanced its understanding of flood risk across its infrastructure, feeding this into its business plan. It has also achieved a significant reduction in its flood insurance premiums.
Anglian Water is England and Wales’s largest water supply and water recycling company by geographic area. It supplies water and water recycling services to almost 7 million people in the East of England and Hartlepool.

The challenge

Identifying assets most at risk of flooding to inform planning

Compared to other regions in the UK, Anglian Water operates in a high proportion of flat and low-lying areas. This gives Regional Flood & Coastal Manager Jonathan Glerum an acute awareness of flood risk to assets – and the knock-on impact this has on service.

Over the years, Anglian Water had commissioned a range of assessments to enhance its understanding of flood risk. “The water industry works to a 5-year asset management planning period,” Jonathan explained. “This gives us the chance to look at flood risk to our assets on a regular basis, present a business plan to Ofwat, and deliver the work we plan.”

In 2022, Anglian Water invited Twinn (formerly known under the Ambiental brand) to tender for its latest asset management planning period. Aiming to build on earlier work, Anglian Water wanted to screen all 7,000 of its above-ground assets – and conduct detailed site assessments at those most at risk of flooding.

Ultimately, it was searching for a partner to support its planning for the 2024 Price Review (PR24), which sets out investment strategy for the years 2025 to 2030, when investments will be made based on the data.

The solution

Understanding and prioritising flood risk exposure across 7,000 assets

Providing site-specific data spanning 19 climate hazards – including pluvial, fluvial and coastal flood risk – Twinn Climate Risk Analytics makes it easy to understand and quantify exposure to climate risks – and delivers results within short timeframes. As a result, it was the ideal solution for Anglian Water’s infrastructure screening requirement.

“As an off-the-shelf product, Twinn FloodScore Climate is incredibly popular among organisations looking to understand how their climate-related risks evolve over time,” said Rob Carling, Channel Sales Manager at Twinn. “Anglian Water liked the simplicity and ease of our approach and methodology. We were also able to collaborate closely with their team throughout the partnership.”

“The volume and speed of the data provided by Twinn was phenomenal,” agreed Jonathan. “As a water company, we have a duty to focus on climate change. Ofwat required us to look at 2- and 4-degree temperature rises, which align with climate change scenarios. Twinn was able to provide data for 4 scenarios rather than 2. For each asset, we had data covering 4 or 5 different epochs, 4 different climate scenarios and 6 or 7 storm duration periods. When we last conducted a climate change assessment 5 years ago, we simply didn’t have this level of detail.”

Working with Twinn, Anglian Water rationalised the data into digestible chunks – overlaying it with consequence scoring to provide a detailed understanding of risk at each asset. “This is crucial from an investment perspective,” elaborated Jonathan. “Some assets serve just 5 or 6 people, whereas others over 100,000 – so the consequence of failure of those two extremes is poles apart.”

By applying consequence scoring to the Twinn data, Anglian Water narrowed over 7,000 assets down to just 25 high-priority sites which required a visit. The Royal HaskoningDHV flood team conducted visits to these sites, providing detailed analysis to help determine the level of protection required and the investment needed.
Heigham Water Treatment Works, Norwich
Electrical equipment raised off the ground to protect it from flooding at a water treatment works in Norfolk

Working with Twinn has been incredibly valuable – and fantastic value for money. 50% of our 7,000 assets are at risk of flooding, so the challenge for us is identifying those we want to protect. By rationalising the data and combining it with consequence scoring, we’ve been able to focus on areas where the risk is greatest and identify what we need to do to mitigate that risk.

Jonathan GlerumRegional Flood & Coastal Manager

The result

Informed investment planning – and reduced insurance premiums

Twinn has enhanced Anglian Water’s understanding of how flood risk and climate change will impact its assets – and is helping to shape its immediate and longer-term climate risk planning and investment strategy.

“It’s fascinating to look at how various climate scenarios – 2 and 4 degrees, for example – will impact us,” said Jonathan. “And from an investment perspective, we’re using Twinn data to help us decide whether it’s better to phase investment over the longer term or act immediately.”

“Of course, this isn’t a once-in-a-lifetime exercise,” continued Jonathan. “It’s a continuous improvement process, and our understanding of the impact of climate change and ability to model it will change in the coming years.”

One surprising insight provided by Twinn data is that climate change does not always make things worse: “In some cases, there are marginal improvements in fluvial flood risk due to lower base flows into rivers,” Jonathan said. The data has also influenced drainage and wastewater planning and fed into Anglian Water’s long-term delivery strategy, a 25-year planning project requested by Ofwat.

Another unintended but welcome consequence of working with Twinn has been a significant reduction in Anglian Water’s insurance premiums. “When renegotiating our flood insurance policy, we were able to demonstrate a detailed understanding of flood risk,” explained Jonathan. Anglian Water leveraged asset-specific data provided by Twinn to inspire confidence among insurers providing flood-related coverage. “The resulting reduction in premium payments saved us more than the cost of the data – and translates to savings for our customers.”

“We’re always challenging ourselves to be innovative,” said Jonathan. “And what we’ve achieved with Twinn is a big step forward on where we were 5 years ago.” Looking ahead to the review in 5 years’ time, Anglian Water is planning to reflect by comparing our data with action taken on site. It will also feed our data into the resilience team to inform flood emergency response planning, as it has done with flood data over the years.

“Working with Twinn has been incredibly valuable – and fantastic value for money,” concluded Jonathan. “50% of our 7,000 assets are at risk of flooding, so the challenge for us is identifying those we want to protect. By rationalising the data and combining it with consequence scoring, we’ve been able to focus on areas where the risk is greatest and identify what we need to do to mitigate that risk.”
Rob Carling - Channel Sales Manager


Channel Sales Manager